Regalianus

Regalianus, governor of Pannonia, was proclaimed emperor by the local legions during the Crisis of the Third Century. His usurpation was a response to barbarian invasions and the perceived weakness of Gallienus's central authority.

Regalianus's brief reign ended when he was defeated and killed in battle against the Roxolani, a Sarmatian tribe that had invaded Pannonia. His death occurred shortly after his proclamation, and his rebellion collapsed.